Sheet metal sprocket chain link and method of making the same



April 25, 1950 A. T. KRUEGER SHEET METAL SPROCKET CHAIN LINK AND METHOD OF MAKING THE SAME Filed Aug. 9, 1944 Patented Apr. 25, 1950 SHEET METAL SPROCKET CHAIN LINK AND METHOD OF MAKING THE SAME Alford '1. Krueger, Milwaukee, Wis., assignor to Chain Belt Company, Milwaukee, Wis., a corporation of Wisconsin Application August 9, 1944, Serial No. 548,662

7 Claims. 1

The invention relates to sprocket chains, and has for its principal object the provision of a simple and relatively inexpensive one-piece sheet metal l'nk for such chains, and a method of making the same which may be conveniently performed by successive die stamping operations.

Briefly stated, the link comprises a pair of spaced parallel side bars which are connected by an integral transverse bridge or cross bar element, an integral extension of which is formed to constitute a pintle barrel or sleeve disposed between the side bars below the bridge and preferably having its end portions received in alined apertures in the side bars.

For purposes of disclosure one typical example of such a link has been shown in the accompanying drawing forming a part of this specification, with several figures of the said drawing also illustrating the various stages in the proce sing of a sheet metal blank to produce such link; it

be'ng understood however, that those skilled in the art may readily vary the precise details of construction of the link, as well as the precise sequence of steps constituting the process of making it, without departing from the spirit of the invention as defined in the appended claims.

In the said drawing:

Figure 1 is a plan view of a sheet metal blank from which the typical one-piece link is to be formed;

Fig. 2 is a similar view illustrating the next Fig. 5 is a plan view of a pair of the completed links in the relations they occupy when assembled into a strand of chain; and

Fig. 6 is a side elevational view of the links shown in Fig. 5.

Referring more particularly to the said drawing. a blank ill, of generally rectangular conformation as shown in Fig. 1, is stamped from a sheet or strip of metal of suitable thickness. The corners of the blank are preferably rounded sub stantially as shown in said figure, and either as a part of said initial stamping operation or subsequent thereto, holes ll, !2, l3 and M are punched through the blank adjacent the respective corners. The holes l3 and M, which receive the connecting pintle when the links are assembled into a strand of chain, may be truly circular as shown, while the holes H and [2 are of irregular conformation, having segmental lugs 15 and I6, here shown as of approximately in angular extent, and of a radius substantially the same as that of the holes l3 and M. The radius of the major portion of the holes I l and it, which in the instance shown is of substantially 270 in extent, is approximately that of the segmental lugs 15 and [6, plus the thickness of the metal from which the blank is formed. The blank may also be provided with a pair of small perforations I! intermediate the holes H and I2. to relieve distortion at the corners of parts which are subsequently bent as will presently appear.

As a part of the in'tial stamping operation, or as an operation subsequent thereto. a portion of a central zone of the blank lying between the holes II and I3 on one side and the holes I2 and M on the other. is struck out to form a tongue 29 having a body portion 2| and a narrower neck 22 with inclined shoulders 23 at their juncture. The neck 22 extends in to the perforations l1, between which it remains integrally connected to that portion 21 of said blank zone which is not severed from the blank in the tongue-forming operation. However, the tongue is bent at this point, along approximately the plane indicated by the broken line 24 in Fig. l, to a position substantially at right angles to the remainder of the blank, as shown in Figs. 2 and 3. At this stage the blank, when viewed in plan as in Fig. 2,

presents a pair of spaced legs 25 and 25 which which subsequently becomes the bridge or cross bar element of the link, all as will presently appear.

The right hand portions of the legs 25 and 25 (as viewed in Figs. 2 and 3) are ofiset relative to the left hand portions thereof, as indicated at 28; and a lug 29 is struck out of a peripheral portion of the pintle hole [4 for engagement with a fiat upon or recess in the pintle whereby the latter may be restrained against rotation in the holes [3 and I4. By varying the angle of the ofisets 28 the pitch of the link may be varied within limits, as will be readily understood.

As indicated in broken lines in Fig. 3, the body portion 2| of the tongue 29 is next curved to form a partly cylindrical pintle barrel or sleeve 30, the omitted portion of which is of substantially the same angular extent as that of the lugs l5 and I6 in the side bar apertures II and I2. To complete the link the leg portions 25 and 26 are now bent relative to the integral bridge 21, along substantially the planes indicated by the broken lines 3| and 32 (Fig. 2) whereby, as is indicated by broken lines in Fig; 4, theyare brought to spaced parallel positions with the-tongue- 26 and its pintle barrel 30 between them and the end portions of the latter entered into the holes H and I2 which they snugly fit. The lugs i5 and I6 of the said holes are accommodated by the omtted portion of the barrel but engage with the end face of the tongue and with the shoulders 23;

as shown in Fig. 6, whereby theytend-topreventdeformation of the barrel under action of the sprocket teeth.

As will be readily understood, the various operations above described may be easily and relatively inexpensively performed by various well known. punching, bending and/or die stamping machines; and they will result in the production of a one-piecesheet metal sprocket chain link which is'well adapted for numerous-purposes.

What is claimed is:

1'. A one-piece'sheet metal sprocket chain link, comprising a pair of spaced side bars having alined pintle barrel apertures; a cross bar integrally connecting said side bars; and a pintle barrel. integrally connected with said crossbar, disposed between the side bars with its end portions received in said side bar apertures 2. A one-piece sheet metal sprocket chainlink, comprising a pair of spaced: side bars having alined pintle: barrel apertures; and a cross bar integrally connecting said side bars and having an integral. tongue extending at substantially right angles therefrom between the side bars, the free end portion of the tongue being curved. to form a pintle barrel the endsof which are disposed in the sidebar apertures.

3-. A sheet metal sprocket chain link according toclaim 2, wherein at least the end portions of the pintlebarrel are of less than 360 in angular extent, and the barrel apertures of the sidebars are provided with lugs complemental to and receivable in the omitted portions of the barrel.

4. A one-piece sheet metal sprocket chain link, comprising spaced side barshaving alined pintle barrel apertures, a; portion of the tops of said side bars being connected by an integral cross bar elementhaving a depending tongue comprisinga neck portion integrally connected to the cross bar and a wider body portion. which. is

curved to constitute a. pintle barrel-,the ends of said barrel being positioned in thesaidapertures of the sidebars;

5. The-method. of making acne-piece sprocket chain. link from. a generally rectangular blank. of sheet metal, which comprises displacing a portion'of an intermediate zone of the blankto form an angularly disposed tongue one end of which is integrally connected to the blank; curving said tongue to form a pintle barrel; and angularly displacing the portions of the blank at each side of said intermediate zone in planes at right angles to the. plane ofdisplacement. of said tongue, to i'ormside b'arsintegrally connected to the undisplaced portion of said blank zone.

6. The method of making a one-piece sprocket chain link from a generally rectangular blank of sheet metal, which comprises displacing a portion of an intermediate zone of the blank to form atongue extending at substantially right angles to-the undisplaced portion of the zone and integrall y connected therewith; curving the free end portion of said tongue to form a pintle barrel; and, while'malntai'ning the portions of the blank at'each: side of said intermediate zone integrally connected to the undisplaced portion of the latter, angularly displacing said side portions relative to said undisplaced; zone portion in planes at right angles to the plane of displacement. of said tongue,. whereby to form side bars positioned at and engaging the ends of said pintle barrel.

'7. The method of making a one-piece sprocket chain link from a generally rectangular blank of sheet metal; which comprises'providing apertures in opposite side portions of the blank; displacing a portion of a zone of the blank intermediate said side portions to form a tongue which an tends at substantially right angles to and remains integrally connected with the undisplaced portion of the zone; curving the free end portion of said tongue to form a pintle barrel; and, while maintaining said side portions integrally connected to the undisplaced portion ofthe intermediate zone, angularly displacing said side-portions relative thereto in planes at substantially right angles to the plane of displacement of'the tongue, to position the side portions in substantially parallel relation at the respective ends of the pintle barrel and enter such ends into the apertures of the side portions.

ALFORD T. KRUEGER.

REFERENCES crrnn' The following references are of record in the file of this patent:

UNITED STATES PA'I'E N I'S Number Name Date 489,252 Hart Jan. 3, I893 958,675 Price May 1'7, 1910 1,584,793 Morehead et al. May 18, 1926 1,641,536 Hall" Sept; 6, I927 2,272,837 Getz et al Feb. 10, 194.2

FOREIGN PATENTS Number Country Date 204,738 Germany Mar. 30, 1908 

